KR101612760B1 - Heat treating apparatus for hot coil - Google Patents

Abstract

Disclosed is a heat treatment apparatus of a hot-rolled coil. According to an embodiment of the present invention, the heat treatment apparatus of a hot-rolled coil comprises: a heat treatment furnace equipped with a plurality of heating means installed in an insulating wall surface which forms a heating chamber to heat the hot-rolled coil wherein a transport cart to stack and transport the hot-rolled coil is entered in the heating chamber. The plurality of heating means includes: a first burner installed in the heating chamber to control a temperature of the heating chamber; a second burner installed in both side walls of the heating chamber to heat both sides of the hot-rolled coil; and a hot air supply unit to supply hot air to an inner sphere unit of the hot-rolled coil. According to the embodiments of the present invention, provided is the heat treatment apparatus of the hot-rolled coil capable of reducing a deviation of a quality of a material in a width direction when transporting the hot-rolled coil.

Description

[0001] HEAT TREATING APPARATUS FOR HOT COIL [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a heat treatment apparatus for a hot-rolled coil, and more particularly to an apparatus for performing a heat treatment after winding a hot-rolled coil.

In the hot rolling process in the steel manufacturing process, the slab produced in the blast furnace is reheated at a temperature suitable for rolling in a heating furnace, and then the strip is passed through a series of rolling devices such as a roughing mill and a finishing mill, rolled into hot-rolled steel sheets in the form of strips, cooled through a cooling facility, and wound into coils through a winder. The wound hot-rolled coils are placed on a yard, air-cooled, and then shipped to a cold rolling mill or product.

On the other hand, in the air cooling process, the edges of the hot-rolled coils contacting with the atmosphere and the inside of the hot-rolled coils are subject to material deviation according to the difference in cooling rate, which causes the plate breakage or rolling phenomenon during the subsequent cold rolling process, . In order to solve such a problem, Korean Patent Registration No. 10-1431020 discloses a method of reducing the material deviation of the hot-rolled coil by reducing the cooling rate of the edge portion of the hot-rolled coil in the phase change temperature range by applying the hot- .

However, the air cooling of the hot-rolled coil is inevitable during application of the cooled box, and the material deviation due to the hard phase is not reduced, and it is necessary to store the material in the cooled cooling box for a long time. .

Korean Registered Patent No. 1431020 (Announced 2014.08.19)

Embodiments of the present invention are intended to provide a hot-rolled coil heat treatment apparatus that performs a heat treatment capable of reducing a material deviation in the width direction during the feeding of a hot-rolled coil after winding.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a heat treatment apparatus for heat-treating a hot-rolled coil, the apparatus comprising: a heating chamber into which a transporting bogie for transporting the hot- Wherein the plurality of heating means includes a first burner installed in the heating chamber for controlling the temperature of the heating chamber, and a second burner installed in the heating chamber for heating both sides of the hot- A second burner provided on both side walls of the heating chamber for supplying hot air to the inner circumference of the heating chamber and a hot air supply unit for supplying hot air toward the inner circumference of the hot coil.

Further, the hot air supply unit may recover the hot exhaust gas exhausted from the heating chamber and inject the hot exhaust gas toward the inner periphery of the hot-rolled coil.

The first burner may include a flame heating burner, and the flame heating burner may be installed on the upper wall of the heating chamber so that the flame to be sprayed does not directly contact the hot-rolled coil.

And the second burner includes a radiant heating burner for heating both sides of the hot rolled coil by radiant heat, the radiant heating burner including at least a radiant heating burner disposed on the sidewall so as to face the side between the center and the lower end of the hot rolled coil One or more of them may be provided.

The hot air supply unit includes a nozzle for injecting hot air toward the internal winding of the hot-rolled coil, a recovery pipe connected to the exhaust pipe for discharging the hot gas inside the heating chamber and supplying exhaust gas flowing to the exhaust pipe to the nozzle, A damper for regulating the supply of exhaust gas from the exhaust pipe to the recovery pipe, and a blower for providing a blowing force for transferring the exhaust gas flowing through the recovery pipe to the nozzle.

The heat treatment furnace also includes a tunnel-shaped main body having an upper wall and both side walls so as to open the front, rear and lower sides, and the opened lower part is connected to the heating chamber by the transporting carriage And the opened front and rear surfaces can be closed by the opening and closing door provided in the heat treatment furnace.

Further, the heating chamber may form a heat insulating structure by a heat insulating panel disposed on the upper wall, the both side walls, and the upper surface of the conveyance truck, the heat insulating wall.

And a sealing device for sealing the gap between the both side walls and the conveyance carriage when the conveyance carriage is drawn into the heating chamber.

The sealing device may further include a rotary arm rotatably coupled to one side of a lower end of the side wall of the main body and having a heat insulating material for sealing the gap, and a second position where the heat insulating material seals the gap, And a drive unit for driving the rotary arm so as to be movable between positions.

And a control unit for controlling a temperature in the heating chamber, wherein the control unit maintains the temperature in the heating chamber at a temperature higher than the heating target temperature of the hot-rolled coil at an initial stage of heating the hot-rolled coil, The plurality of heating means can be controlled to maintain the temperature in the heating chamber at the heating target temperature.

In addition, the transfer bogie includes two units that can be moved back and forth along the rail on both sides of the heat treatment furnace, and the two transfer bogies can be alternately drawn into and out of the heating chamber.

The embodiments of the present invention can reduce the variation in the material in the width direction by the heat treatment apparatus during the feeding of the hot-rolled coils after winding, thereby improving the productivity of the hot-rolled coils.

1 shows a heat treatment process after a hot rolling process according to an embodiment of the present invention.
2 schematically shows a heat treatment apparatus according to an embodiment of the present invention.
FIG. 3 shows a state in which a conveyance truck according to an embodiment of the present invention is drawn into a heat treatment furnace.
4 schematically shows a sealing device according to an embodiment of the present invention.
5 is a cross-sectional view illustrating an internal structure of a heat treatment furnace according to an embodiment of the present invention.
6 is a view for explaining the arrangement structure of the radiant heating burner according to the embodiment of the present invention.
7 schematically shows a hot air supply unit according to an embodiment of the present invention.
8 is a control block diagram for temperature control of a heat treatment furnace according to an embodiment of the present invention.
FIG. 9 is a graph showing a two-step temperature control method in a heat treatment furnace according to an embodiment of the present invention.
10 is a graph showing a temperature change of a hot-rolled coil when two temperature patterns are applied to a heat-treating furnace according to an embodiment of the present invention.
11 shows two transfer bogies disposed on both sides of a heat treatment furnace according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below are provided by way of example so that those skilled in the art will be able to fully understand the spirit of the present invention. The present invention is not limited to the embodiments described below, but may be embodied in other forms. In order to clearly explain the present invention, parts not related to the description are omitted from the drawings, and the width, length, thickness, etc. of the components may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

FIG. 1 illustrates a heat treatment process after a hot rolling process according to an embodiment of the present invention.

Referring to FIG. 1, the heat treatment process after the hot rolling process according to the embodiment of the present invention includes a hot-melt coil generating step S10, a first cooling step S20, a heat treatment step S30, and a second cooling step S40 .

The hot-rolled coil generating step S10 is a step of manufacturing an AHSS (Advanced High Strength Steel) hot-rolled coil 20 having a tensile strength of 780 MPa or more rolled in the form of a coil by rolling the slab S1. More specifically, the slab S1 is heated to a temperature suitable for rolling in the heating furnace 10, and the slab S1 heated in the heating furnace 10 is heated in the rough rolling facility 11 composed of three to four rolling stands The steel sheet is subjected to a width rolling and a thickness rolling to form a bar S2. Thereafter, in a finishing rolling apparatus 12 composed of six to seven rolling stands, a strip S3 having a desired thickness is rolled to a desired thickness, . Thereafter, the strip S3 is cooled to a predetermined temperature while passing through the cooling step 13, and then supplied to the take-up machine 14. In the take-up machine 14, the strip S3 having been cooled is wound in the form of a coil The hot-rolled coil 20 can be produced. Hereinafter, the slab S1, the bar S2 and the strip S3 will be referred to as a rolled material S. The rolled material (S) is a high strength hot-rolled steel sheet (AHSS), including dual-phase steel (DP steel) and Transformation Induced Plasticity steel (TRIP steel) with a tensile strength of 780 MPa or more. The temperature of the hot-rolled coil 20 at the time of being wound by the winder 14 after hot rolling may be in the range of 500 to 700 ° C.

The primary cooling step S20 is performed at a temperature at which the phase transformation is completed while maintaining a sufficient cooling rate such that hard images (martensite and bainite) are generated at the edge portions of the hot- Room temperature to 400 ° C). Here, the primary cooling step S20 may be performed by cooling the hot-rolled coil 20 to a temperature at which the phase transformation is completed using the temperature difference between the normal temperature and the hot-rolled coil 20 in a state where the primary cooling step S20 is performed on the yard of the factory or the bottom of the coiled warehouse.

In the heat treatment step S30, the hard phase of the edge portion of the hot-rolled coil 20 generated through the first cooling step S20 is heated to the tempering temperature (400 to 700 ° C as the heating target temperature of the hot-rolled coil) Annealing the edge portion of the hot-rolled coil 20 to have a strength similar to the central portion strength of the hot-rolled coil 20 by maintaining the tempering temperature at a tempering temperature (400 to 700 ° C) for a predetermined time. Specifically, in the heat treatment step (S30), in the width direction of the hot-rolled coil 20 from the edge of the hot-rolled coil 20, more than 1/4 of the entire width of the hot-rolled coil 20 The boundary between the hot-rolled coil 20 and the hot-rolled coil 20 is heated to reach the tempering temperature and maintained at the tempering temperature for a certain period of time, It can be softened. In this heat treatment step (S30), by using the heat treatment apparatus 30 to be described later, the edge portion and the inner portion of the hot-rolled coil 20 can be quickly heated and maintained at a uniform temperature.

The second cooling step S40 is a step of cooling the hot-rolled coil 20 having the softened structure through the heat treatment step S30 through the heat treatment device 30 to room temperature. At this time, since the hot-rolled coil 20 is in a softened state, re-curing does not occur according to the cooling rate. However, in order to minimize the influence of internal oxidation by heat treatment, Lt; / RTI >

Hereinafter, a heat treatment apparatus according to an embodiment of the present invention will be described.

FIG. 2 is a schematic view of a heat treatment apparatus according to an embodiment of the present invention, and FIG. 3 shows a state in which a conveyance truck according to an embodiment of the present invention is drawn into a heat treatment furnace.

Referring to FIG. 2, the heat treatment apparatus 30 according to the embodiment of the present invention mainly includes a conveyance truck 40 and a heat treatment furnace 50.

The transport bogie 40 can be used to cool the hot-rolled coil 20 in the primary cooling step S20 while simultaneously carrying the hot-rolled coil 20 generated in the hot-rolled coil generating step S10.

The conveying truck 40 may have a plate-shaped truck body 43 equipped with a wheel 42 that moves along a rail 41 installed on the yard of the factory. The truck body 43 can be moved back and forth along the rails 41 by means of a wheel 42 which can be rotated forward and backward by a drive unit (not shown).

The car body 43 may be made of steel or steel alloy having a high strength for stably supporting the hot-rolled coil 20, and a heat insulating panel 44 made of a refractory material is disposed on the upper surface of the car body 43 .

A plurality of skids 45 may be disposed on the upper surface of the heat insulating panel 44 at predetermined intervals along the longitudinal direction thereof to support the hot-rolled coils 20.

The plurality of hot-rolled coils 20 can be cooled before they enter the heat treatment furnace 50 while being supported by the plurality of skids 45, respectively.

The conveyance truck 40 on which the plurality of hot rolling coils 20 are placed can be moved into the heat treatment furnace 50 by moving along the rail 41. At this time, the heat insulating panel 44 of the conveying truck 40 can form a heat insulating structure under the heat treating furnace 50. For this purpose, the conveyance truck 40 may be provided to have a width slightly smaller than the width of the heat treatment furnace 50, and the length of the conveyance truck 40 may be slightly longer than the length of the heat treatment furnace 50.

This conveyance truck 40 can perform the primary cooling in a state in which the plurality of hot-rolled coils 20 are supported on the skid 45. After the primary cooling is completed, the conveyance truck 40 moves along the rails 41, (50) to form a part of the heat insulating structure of the heat treatment furnace (50). Therefore, it is possible to omit the operation of raising or lowering the plurality of hot-rolled coils 20 on the conveyance truck 40 for the heat-treating operation, so that the waiting time of the hot-rolled coil 20 for the heat-treating operation is remarkably reduced.

The heat treatment furnace 50 may be provided in the form of a tunnel having a size capable of accommodating the conveyance truck 40. The heat treatment furnace 50 is provided with a box-shaped main body 51 having front, rear and lower openings. The inside of the main body 51 is heated by heating the hot-rolled coil 20, The heating chamber 60 can be formed.

When the transporting carriage 40 is inserted into the heat treatment furnace 50, the opened lower portion of the main body 51 is closed by the transporting carriage 40, and the open front and rear surfaces of the main body 51 are closed by the main body Closing door 55 which is slidably installed up and down on the upper and lower doors 51 and 51.

The heating chamber 60 thus has an upper wall 52 of the main body 51 and both side walls 53 and 54 extending downwardly from both ends of the upper wall 52 respectively as shown in Figures 2 and 3, And a heat insulating space sealed by the opening / closing door 55 closing the open front and rear surfaces of the heat insulating panel 44 and the main body 51 of the conveying truck 40 closing the opened lower portion of the main body 51 can do.

Specifically, when the open front and rear faces of the main body 51 are closed, the opening and closing door 55 contacts the heat insulating panel 44 of the conveyance truck 40, The heat transfer panel 40 of the conveyance truck 40 closes the lower portion of the main body 51 to heat the front and rear surfaces of the main body 51 when the conveyance truck 40 is pulled into the heating chamber 60. [ So that the inside of the furnace 50 can form a sealed heating chamber 60.

The wall surface of the heating chamber 60 formed by the opening / closing door 55, the main body 51 and the conveyance truck 40 can be constituted by a heat insulating wall surface for preserving the internal heat. The upper wall 52 and the side walls 53 and 54 are provided with the refractory inside the iron pipe forming the outer appearance and the refractory is installed inside the opening and closing door 55, The heating chamber 60 can be made to have a heat insulating structure.

At this time, a predetermined gap may be formed between the transport bogie 40 and both side walls 53 and 54. A sealing device 70 may be installed at one side of the main body 51 to seal the gap.

4 schematically shows a sealing device according to an embodiment of the present invention.

4, the sealing device 70 is installed at the lower ends of both side walls of the main body 51 so as to seal the gap t formed between the transport bogie 40 and both side walls 53, 54 And may be spaced apart from each other along the longitudinal direction of the main body 51. Hereinafter, the sealing device 70 provided on the side wall 53 of the main body 51 will be described.

The sealing device 70 includes a rotary arm 71 rotatably coupled to one side of the lower end of the side wall 53 of the main body 51, a drive unit 72 for rotationally driving the rotary arm 71, And a heat insulating material 74 disposed at an end of the rotary arm 71 and movable between a first position for sealing the gap t in accordance with the rotation direction of the rotary arm 71 and a second position for spacing the clearance t.

The drive unit 72 includes an electric, electronic, hydraulic or pneumatic cylinder with a rod 73 moving back and forth and the rod 73 can be connected to the rotary arm 71 via a link member 75 have.

The rotary arm 71 is rotatably installed at the lower end of the side wall 53 of the main body 51 so as to be rotatable about the rotation axis. One end of the rotary arm 71 is hinged to the link member 75, And a heat insulating material 74 extending along the longitudinal direction by a predetermined length may be provided. The heat insulating material 74 may be detachably coupled to the other side of the rotary arm 71 so as to be replaceable for maintenance.

The gap t formed between the conveying carriage 40 and the side wall 53 when the conveying carriage 40 enters the heating chamber 60 is transmitted to the rotary arm rotated by the drive unit 72 71), so that the exhaust gas or heat in the heating chamber (60) through the gap (t) can be prevented from leaking to the outside.

A plurality of hot-rolled coils (not shown) mounted on the conveying carriage 40 after the open portion of the main body 51 is sealed by the opening / closing door 55, the conveying carriage 40 and the sealing device 70, A plurality of heating means 80 for heat-treating the edge portions of the heating plate 20 are provided.

FIG. 5 is a cross-sectional view illustrating an internal structure of a heat treatment furnace according to an embodiment of the present invention, and FIG. 6 is a view for explaining an arrangement structure of a radiation heating burner according to an embodiment of the present invention.

5, a plurality of heating means 80 according to an embodiment of the present invention includes a first burner 81 for heating the internal air of the heating chamber 60 for controlling the temperature inside the heating chamber 60, A second burner 82 for heating both sides of the hot-rolled coil 20 arranged inside the heating chamber 60 and an inner portion 21 of the hot-rolled coil 20 arranged inside the heating chamber 60, And a hot air supply unit 90 for heating the hot air.

The first burner 81 may be constituted by a high-speed flame burner that burns fuel and rapidly heats air inside the heating chamber 60 by a flame.

The first burner 81 may be provided on the upper wall 52 to spray the flame in the vertical direction and may be provided on both sides of the hot-rolled coil 20 and in a predetermined direction so that the jetted flame does not directly contact the hot- (E.g., 500 mm or more) apart from each other. This is to prevent the hot-rolled coil 20 from becoming uneven due to the local temperature rise when the flame ejected from the first burner 81 directly contacts the hot-rolled coil 20. [

The second burner 82 is for rapidly heating the both side edge portions of the hot-rolled coil 20, and burns the fuel on the plate-like porous heat-generating surface to radiate heat from both sides of the hot- And a flat flame burner.

The second burner 82 can be disposed on both side walls 53 and 54 facing opposite sides of the hot-rolled coil 20 disposed in the heating chamber 60, It can be positioned on the side wall 53 so as to face the side between the center and the lower end of the hot-rolled coil 20 as shown in Fig. 4 in consideration of the difference between the upper and lower temperatures of the second burner 82, Two or more heaters may be disposed on both sides of the side of one hot-rolled coil 20 so as to be heated at a uniform temperature in the circumferential direction of the hot-rolled coil 20. [

The hot air supply portion 90 is for heating the inner winding portion 21 of the hot-rolled coil 20 having a relatively slow heating speed while the hot-rolled coil 20 is heated by the hot gas in the heating chamber 60. That is, the inner portion 21 of the hot-rolled coil 20 is far from the flames of the first burner 81 and the second burner 82 and corresponds to a portion where the flow of the combustion gas is insufficient, And becomes slower than other portions of the coil 20. [ Therefore, the hot air supply unit 90 can reduce the temperature deviation generated in the inner winding part 21 of the hot-rolled coil 20 as hot air is sprayed to the inner winding part 21 of the hot-

7 schematically shows a hot air supply unit according to an embodiment of the present invention.

Referring to FIG. 7, the hot air supply unit 90 according to the embodiment of the present invention recovers hot exhaust gas discharged from the heating chamber 60 and supplies the hot exhaust gas to the inner winding part 21 of the hot- .

To this end, the hot air supply unit 90 includes a nozzle 91 installed on both side walls 53 and 54 so as to face the inner portion 21 of the hot-rolled coil 20 disposed in the heating chamber 60, A recovery pipe 92 connected to the exhaust pipe 59 through which the hot gas inside the exhaust pipe 59 is exhausted to supply the exhaust gas flowing to the exhaust pipe 59 to the nozzle 91, A damper 93 for regulating exhaust gas supply to the recovery pipe 92 and an air blower 94 for providing a blowing force for transferring the exhaust gas flowing through the recovery pipe 92 to the nozzle 91.

With this configuration, the combustion gas generated by the first burner 81 and the second burner 82 first heats both sides of the hot-rolled coil 20 and the outer periphery thereof, and then exhausts the same through the exhaust pipe 59 do. At this time, the temperature of the exhaust gas exhausted through the exhaust pipe 59 is about 700 to 800 degrees. In this case, the hot air supply unit 90 adjusts the opening degree of the damper 93 so that the exhaust gas flowing in the exhaust pipe 59 flows into the recovery pipe 92 and then flows through the nozzle 91 to the inside of the hot- The inner sheet portion 21 of the hot-rolled coil 20 having a relatively slow heating rate can be rapidly heated.

Hereinafter, a heat treatment method using a heat treatment apparatus according to an embodiment of the present invention will be described.

First, as shown in FIG. 1, the hot-rolled coils 20 manufactured through the hot-rolled coil generating step S10 are carried and stacked on the skid 45 of the feed truck 40.

The hot-rolled coil 20 mounted on the conveying truck 40 is air-cooled while maintaining a sufficient cooling rate until a hard phase is generated at both side edge portions.

Thereafter, the conveyance truck 40 moves along the rail 41 and enters the inside of the heat treatment furnace 50.

When the opening and closing door 55 provided on the main body 51 is closed and the sealing device 70 is closed by the conveying carriage 40 and both side walls 53, 54 are closed to perform a heat treatment operation while the heating chamber 60 is closed.

At this time, since it is not necessary to transfer the hot-rolled coil 20 carried by the transfer truck 40 again for the heat treatment operation, the heat treatment time is reduced. 11, when two or more transport bogies 40 are provided, one transport bogie 40 enters the heat treatment furnace 50, and while the hot-rolled coil 20 is heat-treated, The heat exchanger 40 is operated to perform the first cooling process in a state where the hot-rolled coil 20 is loaded, and after the heat treatment is completed in the heat treatment furnace 50 after the waiting, when one feed bogie 40 is taken out, 40 can directly enter the heat treatment furnace 50, so that the operating rate of the heat treatment furnace 50 can be increased. The two transport bogies 40 and 40a are provided so as to be movable back and forth along the rail 41 on both sides of the heat treatment furnace 50 so that one transport bogie 40 is disposed on the open front side of the heat treatment furnace 50 The other transporting carriage 40a waits outside the heat treatment furnace 50 while being heated in the heat treatment furnace 50 so that the heat treatment furnace 50 is completed and the heat treatment furnace 50 is opened, The other conveying carriage 40a is drawn into the heat treatment furnace 50 through the opened rear face of the heat treating furnace 50. [

After the heating chamber 60 is sealed, the heat treatment of the hot-rolled coil 20 is performed while controlling the temperature of the heating chamber 60 through the plurality of heating means 80.

At this time, the temperature control of the heating chamber 60 for the heat treatment of the hot-rolled coil 20 is performed based on the temperature sensed from the temperature sensor 98 that senses the temperature inside the heating chamber 60 as shown in Fig. 8 And a control unit 100 for controlling the heating means 80 of the apparatus.

The control unit 100 may appropriately set the temperature of the heating chamber 60 in consideration of a different initial temperature depending on the type of the hot-rolled coil 20. [

9, the control unit 100 controls the temperature of the heating chamber 60 to be higher than the upper limit temperature for heat treatment (heating target temperature) of the hot-rolled coil 20 at the initial stage of heating during reheating of the hot- A plurality of heating means 80 are first driven to keep the temperature of the heating chamber 60 at a rapid rate so that the surface temperature of the hot-rolled coil 20 does not exceed the heating target temperature, 60 can be lowered to the upper limit temperature, and then the second heating means 80 is driven to be secondarily driven so as to keep the temperature constant.

10 is a chart showing the temperature change at the surface of the hot-rolled coil and the edge portion 300 mm when the temperature control in the heating chamber of the present invention is performed.

In FIG. 10, when the temperature of the heating chamber is kept constant at 700 ° C. and the initial temperature is maintained at 900 ° C. for 1 hour 30 minutes and then maintained at 700 ° C. for the heat treatment time, the two heat treatment times are 300 mm When the temperature of the heating chamber 60 according to the embodiment of the present invention is controlled to be 9.5 hours and 11.5 hours, respectively, when compared with the arrival time at 550 [deg.] C, the heat treatment time can be shortened by about 2 hours I have.

On the other hand, during the heat treatment operation of the hot-rolled coil 20 in the heating chamber 60, both side edge portions of the hot-rolled coil 20 cooled by using the plurality of heating means 80 and the inner- And can use the high temperature exhaust gas exhausted from the heating chamber 60, so that the energy saving effect can be obtained.

When the heat treatment operation is completed in the heating chamber 60, the conveyance truck 40 moves along the rail 41 to be drawn out from the heat treatment furnace 50, and then is conveyed to a plurality of hot rolling coils 20). ≪ / RTI >

The foregoing has shown and described specific embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined in the appended claims.

10: heating furnace, 11: rough rolling facility,
12: finishing rolling equipment, 13: cooling process,
14: Winder, 20: Hot-rolled coil,
30: heat treatment apparatus, 40: conveyance truck,
41: rail, 43: truck body,
44: Insulation panel, 45: Skid,
50: heat treatment furnace, 51: main body,
55: opening / closing door, 60: heating chamber,
70: sealing device, 71: rotating arm,
72: driving unit, 74: heat insulating material,
80: heating means, 81: first burner,
82: second burner, 90: hot air supply part,
91: nozzle, 92: recovery pipe,
93: damper, 94: blower,
98: temperature sensor, 100: control section.

Claims (11)

A heat treatment apparatus for heat-treating a hot-rolled coil,
And a heat treatment furnace provided on the heat insulating wall surface forming the heating chamber and having a plurality of heating means for heating the hot-rolled coil, wherein the heat-
Wherein the plurality of heating means includes a first burner for heating the air in the heating chamber for controlling the temperature of the heating chamber and a second burner disposed on both side walls of the heating chamber for emitting heat toward both sides of the hot- A second burner for heating both sides of the coil; and a hot air supply unit provided on a sidewall of the heating chamber for blowing hot air toward the inner portion of the hot-air coil to heat the inner portion of the hot- . The method according to claim 1,
Wherein the hot air supply unit recovers hot exhaust gas discharged from the heating chamber and injects the exhaust gas toward the inner portion of the hot-rolled coil. The method according to claim 1,
Wherein the first burner includes a flame heating burner,
Wherein the flame heating burner is installed on an upper wall of the heating chamber so that a flame to be sprayed does not directly contact the hot-rolled coil. The method according to claim 1,
Wherein the second burner includes a radiant heating burner for heating both sides of the hot-rolled coil by radiant heat,
Wherein the radiant heating burner has at least one or more than one disposed on the side wall so as to face the side between the center and the lower end of the hot-rolled coil. 3. The method of claim 2,
The hot air supply unit includes a nozzle for injecting hot air toward the inner winding of the hot-rolled coil, a recovery pipe connected to the exhaust pipe for discharging the hot gas inside the heating chamber to supply the exhaust gas flowing to the exhaust pipe to the nozzle, A damper for regulating supply of exhaust gas from the exhaust pipe to the recovery pipe, and a blower for providing a blowing force for transferring the exhaust gas flowing in the recovery pipe to the nozzle. The method according to claim 1,
The heat treatment furnace includes a tunnel-shaped main body having an upper wall and both side walls so that the front, rear,
Wherein the opened bottom is closed by the transporting carriage when the transporting carriage is drawn into the heating chamber and the opened front and rear surfaces are closed by the opening and closing door provided in the heat treatment furnace. The method according to claim 6,
Wherein the heating chamber forms a heat insulating structure by the upper wall made of the heat insulating wall surface, the both side walls, and the heat insulating panel disposed on the upper surface of the conveyance rail. The method according to claim 6,
And a sealing device for sealing the gap between the both side walls and the conveyance carriage when the conveyance carriage is drawn into the heating chamber. 9. The method of claim 8,
The sealing device includes a rotary arm rotatably coupled to one side of a lower end of a side wall of the main body and having a heat insulating material for sealing the gap, and a second position for separating the gap from the first position, And a drive unit for driving the rotary arm so as to move the rotary arm. The method according to claim 1,
Further comprising a controller for controlling the temperature in the heating chamber,
Wherein the control unit is configured to maintain the temperature in the heating chamber at a temperature higher than the heating target temperature of the hot-rolled coil at the initial stage of heating the hot-rolled coil, and to maintain the temperature in the heating chamber at the heating target temperature And the heating means of the hot-rolled coil. The method according to claim 6,
Wherein the transfer bogie includes two units installed on both sides of the heat treatment furnace so as to be movable back and forth along the rails,
Wherein the two transfer bogies are alternately drawn into and out of the heating chamber.

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